1. Field of the Invention
The present invention relates generally to an air conditioner system for an automotive vehicle. More specifically, the invention relates to an air conditioner system which can automatically adjust blower speed to control air flow rate. More particularly, the invention relates to an air conditioner system which can automatically change the direction of discharge air.
2. Description of the prior Art
Various automotive air conditioner systems, which automatically adjust discharge air temperature and air flow rate to achieve comfortable conditions in a vehicular cabin, have been proposed. The Japanese Patent First (unexamined) Publication (Tokkai Sho.) No. 57-140216 discloses such an automatic air conditioner system. In the disclosed system, the voltage applied to a blower motor is controlled on the basis of temperature in the vehicular cabin. The voltage is decreased gradually as the cabin temperature approaches the set cabin temperature. Thereafter, when the difference between the cabin temperature and the set cabin temperature is less than 2.degree. C., the voltage applied to the blower motor fluctuates periodically so that the rate of the conditioning air supplied to the vehicular cabin increases and decreases periodically. By this operation, the occupants of the vehicle feel a comfortably fluctuating breeze.
However, in such a conventional system, the voltage applied to the blower motor fluctuates in a similar pattern as long as the cabin temperature is constant. Therefore, when the thermal condition in the vehicular cabin other than the cabin temperature varies, i.e. when the thermal load applied to the occupants of the vehicular cabin due to insolation or solar radiation varies, the ventilation is not suitably altered. That is, when the thermal load is relatively high, for example, in fine whether in the daytime in summer, air flow to the occupants is insufficient to compensate for the high thermal load. On the other hand, when the insolation or thermal load is relatively low, the same air flow is perceived as excessive.